JMB-Jets PC 21 User manual

Instruction Manual PC 21
1Ver. 1.0 28.03.2019 Written by F.W

Before you get start building and setting up your aircraft, please make sure you
have read this manual and understood it.
If you have any question, please don’t hesitate to contact your dealer. Below are
the contact list
Email: kingtech[email protected]om
Liability Exclusion and Damages
You have acquired a kit, which can be assembly into a fully working R/C model
when fitted out with suitable accessories, as described in the instruction manual
with the kit
However, as manufacturers, we are not in a position to influence the way you build
and operate your model, and we have no control over the methods you use to
install, operate and maintain the radio control system components. For this reason
we are obliged to deny all liability's for loss, damage or cost which are incurred due
to the incompetent or incorrect application and operation of our products, or which
are connected with such operation in any way.
This applies to personal injury, death, damage to buildings, loss of turnover and
business, interruption of business or other direct and indirect consequent damages.
In all circumstances our total liability is limited to the amount which you actually
paid for this model.
BY OPERATING THIS MODEL YOU ASSUME FULL RESPONISBILITY FOR YOU
ACTIONS.
It is important to understand that JMB is unable to monitor whether you follow the
instructions contained in this instruction manual regarding the construction,
operating and maintenance of the aircraft , nor whether you install and use the
radio control system correctly .For this reason we are unable to guarantee, or
provide, a contractual agreement with any individual or company that the model
you have made full function correctly and safely. You, as operator of the model,
must rely upon your own expertise and judgment in acquiring and operating this
model.
2Ver. 1.0 28.03.2019 Written by F.W

Attention !
This aircraft is a high end product and can create an enormous risk for both pilot and
spectators .
If not handled with care& used according to the instructions.
Make sure that you operate your PC21 according to the laws and regulations from the
governing model flying in the country of use. The engine, landing gear, servo, linkages
and control surfaces have to be attached properly. Please use only the recommended
servos and accessories. Make sure that the Centre of Gravity's is located in the
recommended place. Use the nose heavy end of the CG range for your first flights. A
tail heavy plane can be an enormous danger for you and all spectators. Fix any
weights and heavy items like batteries , very securely into the plane. Make sure that
the plane is secured properly when you start the engine. Have a helper hold your
plane from the nose before you start the engine. Make sure all spectators are far
behind, or far in front of the aircraft when running up the engine. Make sure that you
range check your R/C system thoroughly before the 1st flight. It is absolutely necessary
to range check your complete R/C installation first WITHOUT the engine running.
Leave the transmitter antenna retracted or incase of 2.4ghz depress the range check
button and check the distance you can walk before FAILSAVE occurs. Then start the
engine, run at about half a throttle and repeat the range check. Make sure that there
is no range reduction before FAILSAVE occurs. If the range with engine running is less
then with the engine off, please don’t fly at that time. Check that the wing and stab
retaining bolts are tight and that all linkages are secured. Please don’t ignore our
warnings, or those provided by other manufactures. They refer to things and
processes which, if ignored could result in permanent damage or fatal injury.
Important/General Notes
Servo Choice
We strongly advise that you use the recommended servos and equipment listed in the
manual.
Building Sequence
The actual building sequence is your choice but it is usually most efficient to start at
the back of the fuselage and work forwards.
3Ver. 1.0 28.03.2019 Written by F.W

Accessories
This list will help you chose the main additional items needed to finish your PC21.
1. Servos 7 high quality Servos all the main control surfaces require a minimum of
15 kg torque
2. Aluminum servo horns or CFK . I use the one from Gabriel-stahlformenbau.de
7 x 992904 Servohorn
7 x CFK Horn 5/20 992710 with 3 mm ballink
1. A receiver power supply such a Powerbox Evolution or Cockpit
2. Turboprop such as Kingtech K45/60 or SPT5 Jetcat
There will be a set of 3D printed parts available such as Linkage fairing, Connector
holder, Tube guiding, scale parts. Please contact your dealer regarding order.
Did you read the hints and warnings above and the instruction carefully? Did you
understood everything in this manual completely ?
Then and only then, let’s start assembling your JMB PC 21, If not please read it again
before you continue.
4Ver. 1.0 28.03.2019 Written by F.W

How to Glue the Plastic Hinge in
My Personal favorite
are the UHU Endfest 300,
I do not recommend to use
any 5 min Epoxi for this work step.
Fill the Hole on one side with the
mixed glue, you can use a Siring
or just a small Wood to fill it up a bit,
if the glue goes around 5mm in to the
hole is enough.
Apply on the Plastic hinge until half
way around also Glue and push the hinge in .
5Ver. 1.0 28.03.2019 Written by F.W

How to Glue the Plastic Hinge in
Repeat this Work until all hinges are in,
Make sure the Orientation of the hinge
is 90 degree to the hinge line.
Fill the Hole on one side with the
mixed glue, you can use a Siring
or just a small wood to fill it up a bit,
if the glue goes in around 5mm to the
hole is enough then push all the hinge´s in.
Notice , clean around if the Glue squishing
out and keep a 1 mm gap between both parts
Apply on the plastic hinge until half
way around also Glue same you did already
on the opposite side.
6Ver. 1.0 28.03.2019 Written by F.W

How to Glue the Plastic Hinge in
1mm Gap
7Ver. 1.0 28.03.2019 Written by F.W

How to Glue the CFK Horns in
I'm decide to use this Horns because
they look much nicer as the ones which
coming with the Kit.
The Order number you can find on
Page 4.
Mark the right position and drill 2 x 5,5
mm holes , be careful that you not going
to drill all way through the Part!
after remove the Cover film.
Fill the holes with Glue apply also a bit on
the flat surface and push the Horn in.
8Ver. 1.0 28.03.2019 Written by F.W

Fin
9
Ver. 1.0 28.03.2019 Written by F.W
Mount the Servo, the output shaft
face to the leading-edge.
Now push the Servohorn against
the Balsa blanking, you can feel now
On the outside where you have to
start cutting the hole .

Vertical Stabilizer
10Ver. 1.0 28.03.2019 Written by F.W
Start with a small hole and make sure
You are on the right Spot.
Open the Hole until you can see the
Horn. Use tape for mark the size of
The slot

Vertical Stabilizer
11Ver. 1.0 28.03.2019 Written by F.W
Glue the CFK Horn like you see on
Page 8.
Finish the Linkage , I use a 3mm
Threaded rod because the Linkage
Supplied in the Kit was not usable
Mount the Servohorn cover by glue or Screwing
(The cover set you can buy separate)

Horizontal stabilizer
12
Ver. 1.0 28.03.2019 Written by F.W
Mount the Servo the output shaft
face to the trailing-edge.
Glue the CFK Horn in like you see on
Page 8.
Finish the Linkage , I use a 3mm
Threaded rod because the Linkage
Supplied in the Kit was not usable

Horizontal stabilizer
13
Ver. 1.0 28.03.2019 Written by F.W
Mount the Servohorn cover by
Glue or Screwing
(The cover set you can buy separate)
I face the
problem that one
Stab are not align
properly.
It mean there
was a gap from
around 5 mm on
the front pin, so I
decide to modify
the mounting by
add 2 screws .

Horizontal stabilizer
14Ver. 1.0 28.03.2019 Written by F.W
First I open the front pinhole to the
size of 3 x 15 mm. this area is reinforced
With plywood from inside.
the same you have to do on the stab side
I cut from GFK sheet (CFK or similar
Is also ok) a strip with 115 x 15 mm
After I glued it in to the fuselage
Mark the Position of the tongue
With a piece of tape and slide the
Stab on
The tongue should look out 15mm

Horizontal stabilizer
15Ver. 1.0 28.03.2019 Written by F.W
Drill a hole with 2,5mm through all
Remove the Stab and cut a M3 thread
in the tongue.
In the stab you need to drill a 3mm hole
Now the Stab fit perfect

Wing
16Ver. 1.0 28.03.2019 Written by F.W
After you finish gluing the Aileron
and Flap hinges in you can start to
assemble the Servos on the
Hatches.
All Servos need to assemble like
that the Servo output shaft face to
the trailing edge.
Glue the CFK Horn in like you see on
Page 8.

Wing
17Ver. 1.0 28.03.2019 Written by F.W
Finish the Linkage , I use a 3mm
Threaded rod because the Linkage
Supplied in the Kit was not usable
Mount the Servohorn cover by
Glue or Screwing
(The cover set you can buy separate)

Wing
18Ver. 1.0 28.03.2019 Written by F.W
I sprayed my retract Door and
support with Granit design color
which you can buy at some
Hardware shops, it looks much
nicer and the wood is a moister
resist
Drill in each support a 3,5mm hole
for guiding the brake tube or cable.

Wing
19Ver. 1.0 28.03.2019 Written by F.W
Notice :
Make sure all screws from the
retract are tight by using Loctite .
Also check if you have the
pneumatic version the Cylinder
are not leaking.
Assemble the Strut with the Door
support as you can see
Also connect the pressure lines
(Cables)
Screw the Retract with the
M4x15 in by using Loctite.
The routing of the Pneumatic
Tubes or Cables which come from
the retract take the same route as
the Servo cable for the Ail and Flap.

Wing
20Ver. 1.0 28.03.2019 Written by F.W
The Coverplate get screwed on
with the 2 mm wood screws.
Screw the door on and adjust it to
the door outline on the wing,
There should be a gap from around
2mm between the door and the
wing door outline .
Glue the support on the Retract
Strut by using Silicon